What impact will increasing renewable energy consumption have on economic growth? What is the direction or magnitude of the impact and the determinants behind it? Existing research on the ...relationship between renewable energy and economic growth focuses on the linear relationship, whereas ignoring the non-linear relationship between them. In this study, the nonlinear relationship between renewable energy and economic growth in OECD countries was investigated by developing panel threshold regression models. Non-renewable energy intensity, urbanization level and per capita income are used as threshold variables to explore the internal mechanism of renewable energy for economic development. Three panel threshold models are developed based on these three threshold variables. The results show that the effect of renewable energy consumption on economic growth is positive, which indicates that increased renewable energy consumpiotn contributes to economic growth. In addition, this positive relationship changes as the threshold value changes, which means that the role of increasing renewable energy consumption to promote economic development is nonlinear. In other words, if the EU countries increase their renewable energy consumption by more than a certain amount (threshold value), the role of renewable energy consumption in promoting economic development is more significant.
•Analyzing renewable energy and economic in OECD countries.•The fixed-effect model and non-linear threshold model are employed.•Three factors were used as threshold variables to explore the mechanism.•Renewable energy has a threshold effect on economic growth.
Carbon emissions and population aging have risen as two major challenges of the sustainable development of human society. This study explores the nonlinear effects of population aging on carbon ...emission by developing a panel threshold regression (PTR) model, using data from 2002 to 2012 of 137 countries or regions. In the PTR model, carbon emission is the explained variable, whereas population aging is the threshold variable; industrial structure and urbanization are the explanatory variables; and level of economic development, trade freedom, population size, and financial level are the four control variables. With the increase in population aging, the correlation between industrial structure and carbon emissions in the high-income, upper-middle-income, low-income groups are positive, negative, and inverted “U” shaped, respectively. Moreover, with the increase in population aging, the correlations between urbanization and carbon emissions in the high-income group is inverted “U” shaped, whereas the correlation in upper-middle-, lower-middle-, and low-income- groups is nonlinear and positive.
Display omitted
•The effects of different aging lever on carbon emissions are explored.•The Panel Threshold Regression is devloped with the panel data of 137 countries.•Industrial structure and urbanization contribute carbon emissions with aging as the threshold.•Different income groups have different effects.
•Provides a historical review of China’s three generations of new towns since 1949.•Illustrates how China’s new town movements are essential state strategies and projects in different ...periods.•Reveals the continuities and changes in China’s new town movements.•Characterizes the “new town syndrome” and provides a critique of China’s new town models.
The remarkable growth of new towns in China in the past two decades has amazed the world. How shall we make sense of these mushrooming megaprojects, which profoundly reshape the social and economic landscape not only within China but also globally? Successive reports of epic failures – with many projects evolving into ghost towns – further obscure the picture. Existing literature has been useful in highlighting the political-economic logic behind China’s new town frenzy, attributing the latter to China’s marketization, decentralization, and globalization. These accounts, however, focus mostly on the recent past. Lacking a truly longitudinal approach, they tend to lose sight of the underlying links between the socialist past and the postsocialist present. This paper offers a relatively holistic historical review of China’s three new town movements since 1949. While problematizing these historical processes, the paper draws insights from the theory of new state spaces, viewing new town development as a distinctive spatial strategy and project of the state to facilitate accumulation, social regulation, and state-building during specific historical periods. Based on such theoretical constructs, the paper reveals the historical trajectory and patterns of China’s new town movements in the past seven decades.
International research collaboration plays an important role in the social construction and evolution of science. Studies of science increasingly analyze international collaboration across multiple ...organizations for its impetus in improving research quality, advancing efficiency of the scientific production, and fostering breakthroughs in a shorter time. However, long-run patterns of international research collaboration across scientific fields and their structural changes over time are hardly known. Here we show the convergence of international scientific collaboration across research fields over time. Our study uses a dataset by the National Science Foundation and computes the fraction of papers that have international institutional coauthorships for various fields of science. We compare our results with pioneering studies carried out in the 1970s and 1990s by applying a standardization method that transforms all fractions of internationally coauthored papers into a comparable framework. We find, over 1973–2012, that the evolution of collaboration patterns across scientific disciplines seems to generate a convergence between applied and basic sciences. We also show that the general architecture of international scientific collaboration, based on the ranking of fractions of international coauthorships for different scientific fields per year, has tended to be unchanged over time, at least until now. Overall, this study shows, to our knowledge for the first time, the evolution of the patterns of international scientific collaboration starting from initial results described by literature in the 1970s and 1990s. We find a convergence of these long-run collaboration patterns between the applied and basic sciences. This convergence might be one of contributing factors that supports the evolution of modern scientific fields.
In January 2013, a long-lasting episode of severe haze occurred in central and eastern China, and it attracted attention from all sectors of society. The process and evolution of haze pollution ...episodes were observed by the ＂Forming Mechanism and Con- trol Strategies of Haze in China＂ group using an intensive aerosol and trace gases campaign that simultaneously obtained data at 11 ground-based observing sites in the CARE-China network. The characteristics and formation mechanism of haze pollu- tion episodes were discussed. Five haze pollution episodes were identified in the Beijing-Tianjin-Hebei （Jing-Jin-Ji） area; the two most severe episodes occurred during 9-15 January and 25-31 January. During these two haze pollution episodes, the maximum hourly PMz5 mass concentrations in Beijing were 680 and 530 ~tg m-3, respectively. The process and evolution of haze pollution episodes in other major cities in the Jing-Jin-Ji area, such as Shijiazhuang and Tianjin were almost the same as those observed in Beijing. The external cause of the severe haze episodes was the unusual atmospheric circulation, the depres- sion of strong cold air activities and the very unfavorable dispersion due to geographical and meteorological conditions. How- ever, the internal cause was the quick secondary transformation of primary gaseous pollutants to secondary aerosols, which contributed to the ＂explosive growth＂ and ＂sustained growth＂ of PM2.5. Particularly, the abnormally high amount of nitric ox- ide （NOx） in the haze episodes, produced by fossil fuel combustion and vehicle emissions, played a direct or indirect role in the quick secondary transformation of coal-burning sulphur dioxide （SO2） to sulphate aerosols. Furthermore, gaseous pollutants were transformed into secondary aerosols through heterogeneous reactions on the surface of fine particles, which can change the particle＇s size and chemical composition. Consequently, the proportion of secondary inorganic ions, such as sulphate and nitrate, gradually increased, which enhances particle hygroscopicity and thereby accelerating formation of the haze pollution.
Aiming at the intersection processing of underground mine scene roadway in 3D virtual environment, a modeling and rendering system of mine roadway 3D virtual environment based on WebGL is ...constructed. The binary spatial bifurcation tree (BSP) is used for roadway intersection modeling, which realizes the construction and rendering of three-dimensional solid geometry of underground roadway, and effectively reduces the modeling complexity. Based on WebWorker multi-thread real-time modeling and loading method of large-scale scene model, a strategy for separating scenario management from modeling is carried out, which can not only build the roadway model dynamically according to the parameters, but also avoid the blocking problems such as user jams and unfriendly interface operation due to the long modeling and loading time of large scene models over 1 G, such as the number of vertices and texture, so as to improve the effect and performance of scene interaction and real-time roaming.
The paper concentrates on the fundamental coordination problem that requires a network of agents to achieve a specific but arbitrary formation shape. A new technique based on complex Laplacian is ...introduced to address the problems of which formation shapes specified by inter-agent relative positions can be formed and how they can be achieved with distributed control ensuring global stability. Concerning the first question, we show that all similar formations subject to only shape constraints are those that lie in the null space of a complex Laplacian satisfying certain rank condition and that a formation shape can be realized almost surely if and only if the graph modeling the inter-agent specification of the formation shape is 2-rooted. Concerning the second question, a distributed and linear control law is developed based on the complex Laplacian specifying the target formation shape, and provable existence conditions of stabilizing gains to assign the eigenvalues of the closed-loop system at desired locations are given. Moreover, we show how the formation shape control law is extended to achieve a rigid formation if a subset of knowledgable agents knowing the desired formation size scales the formation while the rest agents do not need to re-design and change their control laws.
This paper discusses the theory and practice of constructing knowledge graph under the guidance of Xi Jinping’s socialist thought with Chinese characteristics in the new era. The study first adopts ...the Transformer technique based on the BERT model for effectively extracting entity relationships. Then, the article proposes an entity alignment method based on Neural Tensor Network, which enhances the semantic and structural information utilization of entity embedding vectors through optimized NTN and joint knowledge representation learning. In addition, the study employs a knowledge graph link prediction method that combines semantics and paths to fill in missing relations, and applies probabilistic soft logic to solve the inference problem of non-deterministic knowledge. Ultimately, the effectiveness of the constructed knowledge graph is demonstrated through empirical analysis of Xi Jinping’s theoretical dataset of socialist thought with Chinese characteristics in the new era. The results show that the method is more effective in dealing with polysemous words and participle errors than traditional methods, improving the data structuring level. For example, the accuracy of entity alignment is significantly better than the baseline algorithm on different datasets, e.g., on the DBP-WE dataset, its Hits@1, Hits@10 and MRR values are higher than those of the baseline by 4.01-29.49, 1.99-31.05, and 0.036-0.289, respectively. The method of this paper is remarkably effective in improving the performance of the entity alignment task, which is helpful in understanding and applying the Xi Jinping’s thought of socialism with Chinese characteristics in the new era provides new theoretical perspectives and practical methods.
This study explores the synergistic development between smart tourism and the dissemination of He Luo culture, employing a coupling model to elucidate their interrelation. Through a theoretical ...analysis, it establishes a connection between He Luo culture and intelligent tourism, utilizing the entropy weight method to ascertain the significance of various evaluation indicators. An assessment framework is constructed based on selected indicators to gauge the progress of He Luo culture and intelligent tourism. The research develops a coupling degree model to examine their collaborative growth, revealing a transition in the integration of the river Luo culture sector and the tourism industry from a phase of minimal alignment to primarily coordinated development from 2014 to 2020. The coupling and integration degree between tourism and culture industries within a city has seen a significant increase, from a low of 0.41736 to a high of 0.61014, marking an improvement of 0.19278. This investigation provides a theoretical foundation for enhancing Chinas economic development through the joint advancement of He Luo culture and intelligent tourism.
Achieving high deformability in response to minimal external stimulation while maximizing human–machine interactions is a considerable challenge for wearable and flexible electronics applications. ...Various natural materials or living organisms consisting of hierarchical or interlocked structures exhibit combinations of properties (e.g., natural elasticity and flexibility) that do not occur in conventional materials. The interlocked epidermal–dermal microbridges in human skin have excellent elastic moduli, which enhance and amplify received tactile signal transport. Herein, we use the sensing mechanisms inspired by human skin to develop Ti3C2/natural microcapsule biocomposite films that are robust and deformable by mimicking the micro/nanoscale structure of human skinsuch as the hierarchy, interlocking, and patterning. The interlocked hierarchical structures can be used to create biocomposite films with excellent elastic moduli (0.73 MPa), capable of high deformability in response to various external stimuli, as verified by employing theoretical studies. The flexible sensor with a hierarchical and interlocked structure (24.63 kPa–1) achieves a 9.4-fold increase in pressure sensitivity compared to that of the planar structured Ti3C2-based flexible sensor (2.61 kPa–1). This device also exhibits a rapid response rate (14 ms) and good cycling reproducibility and stability (5000 times). In addition, the flexible pressure device can be used to detect and discriminate signals ranging from finger motion and human pulses to voice recognition.
PDF
